Photonic memristors are essential components for neuromorphic optical computing, but their integration with optical waveguide platforms currently relies on complex fabrication procedures with high manufacturing costs. Here we show that thin-film lithium niobate (TFLN), a widely adopted photonic platform, can be transformed into an all-optically controlled memristive material, enabling the direct fabrication of photonic memristors on TFLN without the need for heterogeneous integration. Through a complementary metal–oxide–semiconductor-compatible oxygen-ion implantation process, spatially separated oxygen-doped and defect-rich layers are formed in TFLN, enabling all-optically controlled refractive index modulation. The resulting oxygen-implanted devices exhibit 3-bit multilevel non-volatile memory, ultralow switching energy of hundreds of femtojoules per bit, submicrosecond optical response and long data retention over extended operation. Wafer-scale production of TFLN and complementary metal–oxide–semiconductor-compatible ion implantation thus provide a homogeneous, scalable and programmable material platform for integrated photonic circuits and systems, with the potential for future large-scale photonic neural networks. Oxygen-ion implantation allows the direct fabrication of photonic memristors in thin-film lithium niobate. The resulting devices combine 3-bit non-volatile optical memory, submicrosecond responses and femtojoule-level switching energies.
Quantum-dot light-emitting diodes (QLEDs) are promising candidates for augmented reality, virtual reality and other high-resolution microdisplay applications. For these applications, the QLEDs must sustain high efficiency at high luminance while remaining compatible with device-integration processes. However, blue QLEDs still face pronounced efficiency roll-off and processing-related performance degradation. Here we develop pure-blue-emitting quantum dots based on a CdZnSe core with a compositionally graded ZnSe/ZnSeS/ZnS shell, combined with ZnCl2-assisted surface morphology modulation. This design suppresses surface-trap-related recombination and improves processing robustness. We demonstrate bottom-emission QLEDs at 464 nm with a peak external quantum efficiency of 23.8% and a 95% external quantum efficiency retention at 50,000 cd m−2 (L95). The top-emission QLEDs reached L95 = 270,000 cd m−2 and a blue index of 586. We also demonstrate patterned QLEDs via photolithography with a resolution of 560 pixels per inch and peak external quantum efficiency of 16.5%. Our results demonstrate pure-blue quantum-dot emitters that combine Rec. 2020-near emission, minimal efficiency roll-off at high brightness, compatibility with direct photolithographic patterning and top-emission device integration for advanced display applications. Quantum dots with compositionally graded shells enhance quantum-dot LED performance, achieving pure-blue emission with a peak external quantum efficiency of 23.8%, 95% of which is retained at a luminance of 50,000 cd m−2.
From ultra-precise nanofabrication to sustainable use cases, femtosecond lasers continue to expand their application potential.
The generation and characterization of high-power X-ray attosecond pulses is a challenging research frontier in free-electron laser science. Now, researchers at the Linac Coherent Light Source have demonstrated experimental confirmation and measurement of hard X-ray pulses reaching 100-attosecond durations.
The use of tailored laser fields improves the coherence times of two co-trapped ytterbium isotopes, resulting in the rejection of magnetic-field noise by more than thirty-thousand-fold, opening the way to improved comagnetometry.
